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1. Fix the import error.

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2. Some codes fine tuning.
This commit is contained in:
Yudong Jin
2022-11-26 01:40:49 +08:00
parent 0585f20970
commit 9f883d5888
9 changed files with 206 additions and 45 deletions
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18
codes/python/chapter_sorting/bubble_sort.py
View File

@@ -4,11 +4,9 @@ Created Time: 2022-11-25
Author: timi (xisunyy@163.com)
'''
from include import *
import sys
import os.path as osp
import sys, os.path as osp
sys.path.append(osp.dirname(osp.dirname(osp.abspath(__file__))))
from include import *
""" 冒泡排序 """
def bubble_sort(nums):
@@ -17,11 +15,10 @@ def bubble_sort(nums):
for i in range(n - 1, -1, -1):
# 内循环：冒泡操作
for j in range(i):
# 交换 nums[j] 与 nums[j + 1]
if nums[j] > nums[j + 1]:
# 交换 nums[j] 与 nums[j + 1]
nums[j], nums[j + 1] = nums[j + 1], nums[j]
""" 冒泡排序（标志优化） """
def bubble_sort_with_flag(nums):
n = len(nums)
@@ -30,19 +27,20 @@ def bubble_sort_with_flag(nums):
flag = False # 初始化标志位
# 内循环：冒泡操作
for j in range(i):
# 交换 nums[j] 与 nums[j + 1]
if nums[j] > nums[j + 1]:
# 交换 nums[j] 与 nums[j + 1]
nums[j], nums[j + 1] = nums[j + 1], nums[j]
flag = True # 记录交换元素
if not flag:
break # 此轮冒泡未交换任何元素，直接跳出
break # 此轮冒泡未交换任何元素，直接跳出
""" Driver Code """
if __name__ == '__main__':
nums = [4, 1, 3, 1, 5, 2]
bubble_sort(nums)
print("排序后数组 nums = ", nums)
print("排序后数组 nums =", nums)
nums1 = [4, 1, 3, 1, 5, 2]
bubble_sort_with_flag(nums1)
print("排序后数组 nums = ", nums1)
print("排序后数组 nums =", nums1)

9
codes/python/chapter_sorting/insertion_sort.py
View File

@@ -4,11 +4,9 @@ Created Time: 2022-11-25
Author: timi (xisunyy@163.com)
'''
from include import *
import sys
import os.path as osp
import sys, os.path as osp
sys.path.append(osp.dirname(osp.dirname(osp.abspath(__file__))))
from include import *
""" 插入排序 """
def insertion_sort(nums):
@@ -20,9 +18,10 @@ def insertion_sort(nums):
while j >= 0 and nums[j] > base:
nums[j + 1] = nums[j] # 1. 将 nums[j] 向右移动一位
j -= 1
nums[j + 1] = base # 2. 将 base 赋值到正确位置
nums[j + 1] = base # 2. 将 base 赋值到正确位置
""" Driver Code """
if __name__ == '__main__':
nums = [4, 1, 3, 1, 5, 2]
insertion_sort(nums)

15
codes/python/chapter_sorting/merge_sort.py
View File

@@ -4,11 +4,9 @@ Created Time: 2022-11-25
Author: timi (xisunyy@163.com)
'''
from include import *
import sys
import os.path as osp
import sys, os.path as osp
sys.path.append(osp.dirname(osp.dirname(osp.abspath(__file__))))
from include import *
"""
合并左子数组和右子数组
@@ -43,16 +41,17 @@ def merge(nums, left, mid, right):
def merge_sort(nums, left, right):
# 终止条件
if left >= right:
return # 当子数组长度为 1 时终止递归
return # 当子数组长度为 1 时终止递归
# 划分阶段
mid = (left + right) // 2 # 计算中点
merge_sort(nums, left, mid) # 递归左子数组
mid = (left + right) // 2 # 计算中点
merge_sort(nums, left, mid) # 递归左子数组
merge_sort(nums, mid + 1, right) # 递归右子数组
# 合并阶段
merge(nums, left, mid, right)
""" Driver Code """
if __name__ == '__main__':
nums = [4, 1, 3, 1, 5, 2]
merge_sort(nums, 0, len(nums) - 1)
print("归并排序完成后 nums = ", nums)
print("归并排序完成后 nums =", nums)

32
codes/python/chapter_sorting/quick_sort.py
View File

@@ -4,15 +4,12 @@ Created Time: 2022-11-25
Author: timi (xisunyy@163.com)
'''
from include import *
import sys
import os.path as osp
import sys, os.path as osp
sys.path.append(osp.dirname(osp.dirname(osp.abspath(__file__))))
from include import *
""" 快速排序类 """
class QuickSort(object):
class QuickSort:
""" 哨兵划分 """
def partition(self, nums, left, right):
# 以 nums[left] 作为基准数
@@ -39,10 +36,8 @@ class QuickSort(object):
self.quick_sort(nums, left, pivot - 1)
self.quick_sort(nums, pivot + 1, right)
""" 快速排序类（中位基准数优化）"""
class QuickSortMedian():
class QuickSortMedian:
""" 选取三个元素的中位数 """
def median_three(self, nums, left, mid, right):
# 使用了异或操作来简化代码
@@ -68,7 +63,7 @@ class QuickSortMedian():
i += 1 # 从左向右找首个大于基准数的元素
# 元素交换
nums[i], nums[j] = nums[j], nums[i]
# 将基准数交换至两子数组的分界线
# 将基准数交换至两子数组的分界线
nums[i], nums[left] = nums[left], nums[i]
return i # 返回基准数的索引
@@ -82,10 +77,8 @@ class QuickSortMedian():
self.quick_sort(nums, left, pivot - 1)
self.quick_sort(nums, pivot + 1, right)
""" 快速排序类（尾递归优化） """
class QuickSortTailCall():
class QuickSortTailCall:
""" 哨兵划分 """
def partition(self, nums, left, right):
# 以 nums[left] 作为基准数
@@ -99,7 +92,7 @@ class QuickSortTailCall():
nums[i], nums[j] = nums[j], nums[i]
# 将基准数交换至两子数组的分界线
nums[i], nums[left] = nums[left], nums[i]
return i # 返回基准数的索引
return i # 返回基准数的索引
""" 快速排序（尾递归优化） """
def quick_sort(self, nums, left, right):
@@ -110,24 +103,25 @@ class QuickSortTailCall():
# 对两个子数组中较短的那个执行快排
if pivot - left < right - pivot:
self.quick_sort(nums, left, pivot - 1) # 递归排序左子数组
left = pivot + 1 # 剩余待排序区间为 [pivot + 1, right]
left = pivot + 1 # 剩余待排序区间为 [pivot + 1, right]
else:
self.quick_sort(nums, pivot + 1, right) # 递归排序右子数组
right = pivot - 1 # 剩余待排序区间为 [left, pivot - 1]
right = pivot - 1 # 剩余待排序区间为 [left, pivot - 1]
""" Driver Code """
if __name__ == '__main__':
# 快速排序
nums = [4, 1, 3, 1, 5, 2]
QuickSort().quick_sort(nums, 0, len(nums) - 1)
print("快速排序完成后 nums = ", nums)
print("快速排序完成后 nums =", nums)
# 快速排序（中位基准数优化）
nums1 = [4, 1, 3, 1, 5, 2]
QuickSortMedian().quick_sort(nums1, 0, len(nums1) - 1)
print("快速排序（中位基准数优化）完成后 nums = ", nums)
print("快速排序（中位基准数优化）完成后 nums =", nums)
# 快速排序（尾递归优化）
nums2 = [4, 1, 3, 1, 5, 2]
QuickSortTailCall().quick_sort(nums, 0, len(nums2) - 1)
print("快速排序（尾递归优化）完成后 nums = ", nums)
print("快速排序（尾递归优化）完成后 nums =", nums)